I was actually getting better results with your plugin version than the RACE or BACCH with a L/R width test track, but I'm not completely sure why. It didn't seem to "wrap" around me as much, but it was easer to locate L/R sounds. I wonder if this is room/speaker dependent? I need to experiment more to really confirm this.

RE: speakers to the sides, Optimal Source Distribution is a variation of the ambiopole whereas low frequency drivers (<300Hz) are placed at +/-90 while mids are at 10-15deg and high freq at 0-3deg. It's supposed to be more dynamic. The head is less sensitive to phase differences of low frequency sounds when placed at the sides (hard to localize), so maybe that helps explain that one. I don't know what model for the crosstalk cancellation looks like for this, but there are a few commerical center channel speakers adapting this technology. Look at some of the "soundbar" speakers. Marrantz owns rights to the system labeled "OPSODISP".

Ambiophonics Institute, I think I'm a member, if there is such a thing.

Robin Miller built such a contraption in Audio Mulch with 15 delay sections. I help perform listening tests with this just about every week. The RACE algorithm came out of this. By adjusting the feedback control on a RACE processor, the attenuation of each successive reflection is increased.

Excellent that you are able to have direct communication with him/them. I wasn't sure if there was an "official" institute but was referring more to whomever was working on the concept/ideas.

have played a little bit with a barrier, didn't particularly get too encouraging a result but nonetheless realise that such a perfunctory attempt is nothing to base conclusions on.

Firstly, to those who have tried it and liked it, how would you sum up the results? and in what specific ways are they different/better than standard 2 ch.

I have a pretty good setup atm, but what floats my boat with my system (and have never heard on any other system to date) is the amount of envelopment/ambience that it gives. So any comments in those particular areas regarding ambio will be closely scrutinized

Indeed, it would be of interest to hear from people who have tried it and NOT liked it. Of course, it would need to be confirmed that it was done correctly, no point in passing judgement on ambiophonics if what was tried was, in fact, not ambiophonics (as in my case mentioned above)

In any case, the barrier method would be a big turn off, so your little VST is of high interest.

Being a computer idiot, well actually I think I hate the bloody things!, I had a bit of trouble working out how to get your plugin into winamp, but am rather proud that I made it in the end. Hmm, unzipping it first seemed to be a great help heh heh.

Anyway, I got it into winamp and it even came up! which was my first goal. Worked and all, but at this stage I was just listening from the computer and could hear that it was working, system still set up as standard.

I'm pretty sure that at some stage I must have turned the computer off, and now for neither love nor money can I get it back into the dsp list (in preferences). I know it is in winamp, cause I can find it and see that it is there in the dsp section, but it no longer comes up so I can configure it (or whatever the term is).

Prior to that as an experiment I had loaded some eq type vst from the winamp page, and it still gets listed all the time whereas yours doesn't anymore. And in the plugins I can see them next to each other so right now I'm a bit stumped.

I have tried re-downloading and ( I think) followed the same procedure, but this time around I cannot get it into the list to be enabled.

Is this a known 'bug' and if so do you have any suggestions on how to get around it? TIA

I'm not sure what the background of you guys is, judging from the site there would be a few professionals amongst you, but me I'm just a dumb audio enthusiast. Which leads me to a question re winamp..is it used simply because it allows plugins and that (at least to some) they are reasonably 'easy' to write? On a purely audio quality basis, just where would winamp as a medium rate? Out of curiosity, would there be preferable programs to use?

Anyway, like all things, it's a question of where you are at the end of the day. If you have a more enjoyable listening experience using winamp and ambio than without (assuming for example it is not really a 'top quality' player) then that is a fair enough equation

Anyway, thanks for this plugin and I look forward to giving it a go. No doubt you would be interested in my conclusions!

I'm pretty sure that at some stage I must have turned the computer off, and now for neither love nor money can I get it back into the dsp list (in preferences). I know it is in winamp, cause I can find it and see that it is there in the dsp section, but it no longer comes up so I can configure it (or whatever the term is).

...

Is this a known 'bug' and if so do you have any suggestions on how to get around it? TIA

Great to have you here.

Hmmm. Not sure what your problem is. My plugin is a VST, not a winamp plugin. You have to load the Winamp VST host and then use that to load the VST program. See

There are many VST hosts, but as far as I can tell the sound won't be different in with any them. Thus, Winamp is as good as anything. If you are listening to CDs and mp3s, then Winamp is all you need.

Maybe I shouldn't mention it but be sure to put the speakers close together. _________________--Howard
my music and other stuff

my terminology may be incorrect-sorry-but I did read the link you gave. It was what enabled me to successfully do it once. Tho admittedly it was pretty easy once I had unzipped it

well, maybe not that easy but you get the idea.

as I said, I did manage to get it up and running once, but unfortunately did not take the opportunity then to try it (ie left the system as is), guess I didn't foresee it not working all the time.

Anyway, as a VST I did get it into the dsp folder and got it running. It no longer appears in the dsp listing in preferences, even tho if I get to the plugin folder I can see it in there.

I have tried deleting it and winamp, and re-downloading both and doing it all again. It is always to be found in the plugins folder but now refuses to play the game and appear in the dsp listing within preferences for me

I meant to try this before but forgot, maybe I should try the other program you mentioned (chameleon I think, whatever I'll check after this reply) and I may have more luck with that one (unless it's for mac or something, will find out soon enough) Edit..quintessential.

I have heard from others who have tried the 'mulch' way that it can be good on large scale orchestral works etc, but not so good on electronic type stuff, something to do with 'phasey' bass ( or similar description). This being an electronic music type forum however seems to make that hard to understand.....(unless the mosc ambiophonic is the bees knees heh heh)

Hopefully (soon) I will be able to find out for myself(crossing fingers as I type), but what would be that take of you guys on questions like that? Do you find it's good for some styles of music but not others for example?? Or maybe the description given has something to do with a different implementation??

Anyway, will try it all again, if no luck then I may start a thread in another forum (unless someone here has some tips??) and hope for some 'computer whiz' to be able to spot what I'm doing wrong. The weird bit is that it DID work once???????

EDIT I spent a few minutes looking for the 'I'm a complete blinkin idiot' smiley, but couldn't find it.

Anyway, re-read your link (but had to re-download the bridge...prob because when I re-downloaded winamp I forgot it) and this time used the bridge to load the map

Of course it was always there, but after the initial time I forgot the intermediate step.

Oh well, I've introduced myself to you all, and you now know what you're dealing with... an idiot hah hah.

Have just rearranged my room so will be a while till I get the time to move the speakers once again, but thanks howard I'll get back to you. Still look forward to your thoughts on styles of music etc.

Howard stoped by for a visit and we setup my speakers and his laptop with the MAP-vst plugin and I have to say that it provided the best "stereo" listening experience I've every had. The image is pristine, the speakers absolutely disappear providing a completely solid soundstage over a very wide arc, and the center component attenuation problem of some other algorithms was not apparent. I've been a long time user of the Carver Sonic-holography device and this beats it hands down and it hasn't the apparent timbre/attenuation problems of the RACE algorithm._________________The question is not whether they can talk or reason, but whether they can suffer. -- Jeremy Bentham

Anyway, the Mulch program is the older RACE algorithm with I personally don't like too much. It attenuates the center and has some reverby ringing that causes timbre distortion. RACE is very bad for pop music because a lot of that mixes the vocals directly in the center. The center attenuation isn't as noticeable in orchestral music. The MAP algorithm, IMHO, solves these problems.

Now, about the styles. Most music is mixed with the center having the most important information. The MAP algorithm is designed to reproduce this with as little processing as possible and thus has the least timbre changes there. In most classical, pop, world music, etc, this is great.

In some electronic music, there is ping ponging where sounds are hard panned left and right. This takes advantage of the conventional wide-spaced stereo where sounds seem to bounce from one speaker to another. Ambiophonic will not do as well in these situations.

I'm not sure this is a terrible disadvantage. I find it easier to listen to electronic music for long periods with ambiophonic than with wide-spaced stereo. Electronic sounds come from the soundstage and take on a very nice spaciality that is not possible with wide-spaced speakers.

Dance music is generally composed for a club environment where spacialization, other than ping ponging, is not one of the objectives. Maybe dance music isn't well suited for ambio.

At electro-music 2008 we set up the PA with four speakers using the MAP processor. The results were very well received by people with lots of experience and knowledge. "Beautiful" and "best PA sound I've ever heard" were some of the comments I remember._________________--Howard
my music and other stuff

thanks for the fuller answers to my questions. I do remember my first impressions on martin logans..very clear and transparent, possibly as expected form panels!

This time (tho I'm sure I can get it running again after learning my lesson..what do they say?? RTFM isn't it?? heh heh) I made sure that I did, in fact, take a few minutes to move the speakers close to each other and try it.

As I'm still settling the speakers into their new orientation in the room I haven't spent the (usually) large amount of time required to get them 'just right' so I was not averse to a coupla minutes moving them around, once they are just right my comment to anyone is 'move them on pain of death'!

Look, very very cursory try with it, but first impressions were not great. I mean it was not bad, don't get me wrong, but I did lose the huge soundstage.

I know that it was in no way set up properly (as can be seen above, it takes time to set up the positions properly even with two channel-gee how often do you see idjit audiophiles with huge amounts of dough tied up in their systems just plonk their speakers down any old where???-so please bear that in mind when viewing my initial reservations would you?

The last thing I'd want to do is dissuade anyone reading this from giving it a go based on most likely incorrect implementation!

So I guess a few pointers on order of importances would be handy. The algorithm itself is fixed (except for it's internal parameters of course) so that really only leaves us with speaker positioning right??

Initially I had them pretty well touching, then maybe two or three iterations of gradually widening them.

A good starting point/guide would be about twenty degrees no? I'll have to get the calculator our and work out what that actually is, and start from there. I vaguely recall earlier in this thread some mention of 'headwidth' when mentioning speaker positions...does that somehow mean that is the 'arc' the speakers occupy when viewed from the listening distance?

Another approach is to set the speakers kinda the right width apart and vary the angle by moving the chair along the centre line. From reading in the past I gather that it is the centre line along which it all happens (ie for two people side by side won't really work, but front to back will)?

The centre image was very real and solid, and I could easily discern sounds coming from outside the speakers (which when the speakers are so close if they didn't it would be a complete failure!!)

'Trouble' is that my system has the widest soundstage I've ever heard. Not boasting or harping or whatever on it, but it maaaaay mean that on almost every other system this may increase the soundstage etc etc but perhaps just not on mine. It may be the very rare exception???

So I am serious about giving it a fair and thorough trial, not sure if I can give you any extra needed data or that there may be other variable I need to keep in mind.

The other side of that coin is of course like a lot of things it needs to be lived with for a while! Unfortunately right now and for the next few weeks I don't have that luxury...in a few weeks time we are having our annual gtg and there are a bunch of blokes coming from interstate and all staying the weekend. Haha, last year I cleaned up the listening room (I'm a pig so made a special effort to tidy up for everyone) but in the process of cleaning up (which involved shortening speaker leads draped all over the floor-a lot of them as my system is tri-amped) I managed to hook up the mids out of phase and as I didn't sit in the sweetspot all weekend I didn't notince!! grrrr.

I'm sure you're not really interested in all that but it does mean that this year I will not be changing a thing until the weekend is done and dusted!! So even tho I can afford a few days for a bit more fiddling, in truth the serious evaluation cannot happen till after the gtg.

Hope I don't come across as a typical pompous pious snobbish audiophile with a superior than thou attitude, I really do want to give it a try seriously so I'm just trying to put my first reservations into context for you.

Sorry it isn't working well for you. The algorithm is indeed fixed on this VST. I'm going to make another one with more adjustments, but this one works very well.

Yes, the sweet spot is really a sweet line so people can sit/stand behind each other.

The only time I've seen this not work is when the speakers have drivers that aren't on a vertical line. I have some beautiful old Rectilinear III speakers that sound great but the drivers are not in a vertical line and this crosstalk canceler doesn't work very well. It works best with small near field type monitors.

The angle isn't very critical. If possible set up the speakers and move back and forth. As long as you are on the center line it should work._________________--Howard
my music and other stuff

no really, it was very slapdash indeed. As long as there are no 'really important' things to consider I'll take a bit more care next time, you know making sure that the speakers are as well setup as I would in a normal situation. I just moved them really roughly for a quickish test.

Rest assured I will let you know how I get on.

Funny you should mention the non vertical line of the drivers...at the moment mine are not in fact in a vertical line. Pretty close but not fully. the important ones (tweets and mids) are in a vertical line, but offset from the bass a bit. And as the bass driver crosses at 200 hz it may be more of a problem that when they are crossed lower. good catch.

I'm in the process right now of building the new boxes (which will fix that particular problem) but that too is a while away before they are finished.

Will post back in a few weeks (hopefully a bit sooner) after a rigorous test of it all.

Well, smarter people than me have said that freqs below 500 Hz shouldn't matter in the vertical alignment, but I don't know. The VST works great with small satellite and sub systems._________________--Howard
my music and other stuff

has anyone else run across a bug with this plugin where if you leave the VST host running for extended periods >1day/24 hours the plugin stops responding or is no longer recognized? It's hard to explain but I'm using it in Console and after a while it ends up with a "?" above it and I have to close Console, clear it from task manager and then reopen again. It's as if the memory buffer goes haywire. Maybe it's a Console problem, but the other plugins I'm using don't do this. I did have Farina's X-Volver do it was well. Very odd problem.

On another note, I think this Dave Moulton article fits nicely with your rendition of ambiophonics Mosc. It's not an exact fit, but still fits nicely with it.

Glad you like the plugin. The new version is being beta tested now. It will have user presets so it will be easier for you to keep setting and to experiment by quickly comparing._________________--Howard
my music and other stuff

Glad you like the plugin. The new version is being beta tested now. It will have user presets so it will be easier for you to keep setting and to experiment by quickly comparing.

Any update on this? I've been trying other ambio-based VST plugins (like the V.I stereo to 5.1 converter) and mosc's one seems to provide the best results (i.e. less echo-effect for simulated spaciousness and more natural sound even thought some accuracy is loss). However, if I understand correctly, mosc model does not use recursion or band pass filters like RACE or many other ones. Shouldn't some level of recursion (at least to an audible level) produce better results?

I'm still working on this. We are pretty close to releasing something. I've added recursion so RACE can be done, but IMHO, the recursion adds undesired artifacts. We have pretty much decided that the filters don't do anything good either. So, the free vst is still the best algorithm.

After the great results obtained by the mosc's ambiophonics plugin for stereo reproduction, I've been investigating about ambiophonics correction for a 5.1 setup.

The idea is to correct inter-speaker crosstalks by using several instances of the stereo crosstalk cancellation (i.e. the FL speaker interferes with the FR, CEN, SL and SR speaker; the FR speaker interferes with the FL, CEN, SL and SR speaker and so on).

In order to test this multichannel setup (in which speakers are located in an standard square-like manner), I've used a VST host (Console) and a Virtual Cable to redirect the output's media player to the host, insert several VST plugins and finally output the fully corrected signal through the sound card.

I attach the layout of the Console. Note that, for each speaker, four instances of the mosc's VST plugin are needed to individually correct its interaction against the other ones. In this way the signal is replicated (increased) four times and, in consequence, it should be significantly attenuated (-12db). Before the output you can see a multichannel convolver which models the individual IR responses of each speaker.

So far it worked. The multichannel scene is much more dense and covers the full 360º spectrum both form multichannel disks or movie soundtracks. However, it also sound a little fuzzy with the width parameter set to 10.

I am currently experimenting in individual crosstalks configurations as I assume that for example, the correction between the FL and CEN speakers (which are separated by a 20º angle) should be different from the correction between the FL and SR speakers (which conform a 180º angle between them).

The only parameter in the mosc's plugin is the Width, which suppose it controls the delay applied to the inverse signal, is it correct? The far the speakers are, the higher the value should be or is it the inverse? What do you think on this setup?

Wow. That's great work. We have been thinking of similar things for 5.1 but haven't tried anything yet. I personally don't have a 5.1 set up that is suitable for such tight audio. My home theater setup is for casual TV watching.

I'm sorry to say that your post will take me a long time to digest and understand. I'm in the middle of the big WinterSteam 09 prep now. I will get back to this and post a better response.

The width control on this VST controls the mix between the straight signal and the delay/crosstalk side chain. Wide is probably vertical. No canceling if far left and just the canceling signal is far right. The delay is not adjustable. You are right that the delay should be increased a bit for wider angular separation.

You need a VST with adjustable delay. I have one I'm developing that will be for sale. It's not ready to post up on the store yet though. Lemme think about maybe putting it up on the store with a free-upgrade system. I have to consult my partner in this stuff first though._________________--Howard
my music and other stuff

The width control on this VST controls the mix between the straight signal and the delay/crosstalk side chain. Wide is probably vertical. No canceling if far left and just the canceling signal is far right. The delay is not adjustable. You are right that the delay should be increased a bit for wider angular separation.

Thanks mosc, this makes sense. Which width value do you recommend? With the maximum value it seems to me that the central image becomes too fuzzy, a value between 8 and 9 seems to work better. Do you think the mix value should depend on the relative speaker placement?

I have found another project (http://www.matrixhifi.org/drcop/docs/DRCoP_manual_es_v_0_7.html) which implements the RACE algorithm for crosstalk cancellation. It is in Spanish, but in the configuration window they provide a control to change the attenuation of the inverse signal to be added to the original one (which is similar to a mix control) and a delay control (in addition to a high and low pass filter).

The recommendations for setting those parameters are:
- To decrease the attenuation as the angle between the speakers increase (e.g. 2,3 db of attenuation for a 10-20º of separation and 5-6 db up to 60º).
-To increase the delay (measured in samples) as the angle increases to compensate the difference between the arrival of the original and inverse signals.

mosc wrote:

You need a VST with adjustable delay. I have one I'm developing that will be for sale. It's not ready to post up on the store yet though. Lemme think about maybe putting it up on the store with a free-upgrade system. I have to consult my partner in this stuff first though.

I will try to introduce delays for the mixed signals, even though it will complicate the layout quite a bit . I'll be looking forward to updates in the new VST version. More configurable controls will be certainly very useful for fine tuning.

I've been configuring the multichannel ambiophonic setup. This time I've changed the VST host to AudioMulch as it offers a greater degree of configurability (even though a more basic interface).

The setup for a 7.1 setup is the shown in the attached figure.

Basically, I've been playing with the width control of mosc' pluging. After experimentation, I set:
- A value of 10 (maximum mix) to speakers with form an angle of 20-25º (like the FL and the CENTER channel).
- A value of 9 for speakers with form an angle of 40-50º (such as the FL and the FR or the SL and the SR).
- A value of 8 for speakers with an angle greater than 60º (like the FL agains the SL or the SR).

The individual speaker attenuations and delays are controlled via the Convolver VST plug-in.

The integration with this configuration is better an the soundstage more defined than setting all the mosc's VST instances to 10. As state above, the degree of cancellation should depend of the inter-speaker separation. The final result is a complete 360º soundstage with great localization of the instruments!.

The only issue I've found is that audiomulch is reporting that the default value for the balance control in mosc's VST plugin is 5.19 when it should be 5.

It is certainly on my to do list. We've got all the "circuits worked out" and we're working on what the front panel will look like. Glad to hear you are still interested.

I'm also really overdue on writing an article about using 4 channels in from for electronic music live stage sound reinforcement. We set up a system like this at electro-music 2008 and it was fantastic. Not a bad seat in the house. Sorry to tease, but confessing to having things to do motivates me to work._________________--Howard
my music and other stuff

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